A projectile is thrown in the upward direction making an angle of 60^(@) with the horizontal direction with a velocity of 147 ms^(-1). Then the time after which its inclination with the horizontal is 45^(@), is:

A projectile is thrown in the upward direction making an angle of 60^(

1.	A projectile is thrown in the upward direction making an angle of 60^(@) with the horizontal direction with a velocity of 147 ms^(-1). Then the time after which its inclination with the horizontal is 45^(@), is:
Answer» 15s 10.98s 5.49s 2.745s. Solution :Let the VELOCITY of the projectile is V. `v cos 45^(@)=u cos 60^(@) =u=147m//s` Now, `v SIN 45^(@)=u sin 60^(@)-gt`